Portable roll-forming machines are commonly used in construction for forming strips of metal into siding. In the past, such roll-formers have been able to make only one width of siding. Thus to change from 8 inch siding to 10 or 12 inch siding required a different machine to be brought in. Recently machines have been disclosed which are adjustable for forming different widths of siding from different widths of rolled metal strips.
One such machine is disclosed in U.S. Pat. No. 5,038,592 to Knudsen. The rolls are adjustable by sliding them on their shafts in order to accommodate various widths of material and to produce various sizes of siding.
Other roll-formers have been directed to formed metal products in general, such as roof panels, siding, structural members and eaves-troughs, with accommodation for varying widths of material and product. Examples of these are shown in the following patents:
U.S. Pat. No. 5,740,687 to Meyer PA1 U.S. Pat. No. 5,732,582 to Knudsen PA1 U.S. Pat. No. 5,722,728 to Horino et al. PA1 U.S. Pat. No. 5,394,722 to Meyer PA1 U.S. Pat. No. 5,319,952 to Cadney. PA1 U.S. Pat. No. 5,038,592 to Knudsen PA1 U.S. Pat. No. 4,787,233 to Beymer
The first part of a siding machine, the flat board former, turns the sheet metal strip into a board, which can be installed on a wall as siding in that form. The board has a formed U-channel on the bottom edge and on the top edge either a punched nailing strip or a flange to accept a clamp, along with a lip to accept the upward leg of the U-channel on the next board. The standard nominal widths for such boards are 8, 10 and 12 inches, however regardless of the width, the formed profile is the same on each edge.
For most applications where such machines are used it is necessary to further form the board with a decorative profile. Commonly the board is formed so that when applied it takes on the appearance of two boards rather than one. This done by forming a bend or lap in the middle of the board. This is called a "double 4" on 8 inch siding, "double 5" on 10 inch siding or "double 6" on 12 inch siding. Another popular profile is the "Dutch lap", which is a variation in the look of the double 4, etc. As well as decoration these profiles add strength to the siding.
This decorative forming is accomplished in the second part of the machine, commonly called the transformer, which acts only on the middle of the board, since the top and bottom sides are already finished when the board enters the transformer. Often the transformer has been an optional machine which is simply added on to the end of the flat board former if needed. In some machines, see for example U.S. Pat. No. 4,787,233 to Beymer, the whole transformer is changed in order to change the decorative profile or to accommodate different widths of siding.
In machines designed to accept varying widths of sheet metal strips, it has been a cumbersome and time-consuming task to change from material of one width to material of another, requiring careful adjustment of rollers and guides from one position to another. See for example U.S. Pat. No. 5,038,592 to Knudsen. A quickly and accurately adjustable machine would be desirable.
Present machines as well offer only limited and predetermined variations in width and decorative forming. For sale in areas where metric sizes are in use, a different machine must be built. Decorative designs are also very limited due to the expense of setting up for a different design, or the same design at a different location on the face of the board.
Another problem with existing siding machines is that they start with a jerk, which often causes the strip of sheet metal being fed into them to bind, resulting in a crash when the material ceases to feed. Such crashes result in wasted time and material as the sheet metal strip must be backed out of the machine and portions of bent material must often be cut off and discarded. Another result of such crashes is that breakers are often blown and must be reset. This is a particular problem as often the homeowner is away during the day when the work is being done, and the machine operator does not have access to re-set the breaker.